The United States has blocked demands at the UN security council for an international inquiry into Israel's assault on the Turkish ship carrying aid to Gaza that left nine pro-Palestinian activists dead.

A compromise statement instead calls for an impartial investigation which Washington indicated could be carried out by Israel.

Turkey pressed for the security council to launch an investigation similar to Richard Goldstone's inquiry into last year's fighting in Gaza which prompted protests from Israel when it concluded that Israel and Hamas were probably guilty of war crimes and crimes against humanity.

Ankara wanted the investigation into the raid on the Mavi Marmara to result in the prosecution of officials responsible for the assault and the payment of compensation to the victims.

But in hours of diplomatic wrangling, the US blocked the move and instead forced a statement that called for "a prompt, impartial, credible and transparent investigation conforming to international standards". The US representative at the security council discussions, Alejandro Wolff, indicated that Washington would be satisfied with Israel investigating itself when he called for it to undertake a credible investigation.